Climate Change 101 What is Causing LongTerm Climate

Climate Change 101: What is Causing Long-Term Climate Change? 1 Jessica Blunden Earth Resource Technologies NOAA’s National Climatic Data Center

What Are We Going to Talk About? • How have global temperatures changed in recent years? • What is the difference between Earth’s Natural Greenhouse Effect and the Enhanced Greenhouse Effect? • What are the major Greenhouse Gases and where do they come from? • What is the cause of Earth’s recent increasing temperatures?

Earth’s Atmosphere 3 The Earth’s average temperature would be a very cold -1°F if there was no atmosphere. Fortunately the average temperature is 57°F.

The Natural Greenhouse Effect 4

Natural Greenhouse Gas Sources 5 Carbon Dioxide (CO 2): Variable lifetime (tens to thousands of years) Decomposition, ocean release, plant, animal, and soil respiration, volcanoes. Methane (CH 4): Lifetime is 9 years Wetlands, oceans, volcanoes, wildfires. Nitrous Oxide (N 2 O): Lifetime is 114 years Soils under natural vegetation and oceans.

The Earth is Warming Past 1500 years Recent global temperatures are greater than at least the previous 1500 years. 0. 9 Source: Mann et al, 2008 2015 Looking at the full period of record: 1880 – 2014: + 0. 13°F / decade Looking at the last 30 years: 1985 – 2014: + 0. 29°F / decade

The Natural Greenhouse Effect 7

The Enhanced Greenhouse Effect 8

9 Increasing Greenhouse Gas Concentrations Industrial Revolution

Greenhouse Gas Sources from Human Activities 10

Recent Greenhouse Gas Trends 11 Carbon Dioxide Methane • Additional radiative forcing from greenhouse gases above preindustrial times is now 2. 94 Watts per square meter. • CO 2 contributes to about 2/3 of this forcing. But what does that mean? ? ? Nitrous Oxide • The “extra” CO 2 traps ~23 billion megawatts of energy every day. • The same amount of energy produced in the US during all of 2014.

Are CO 2 and other greenhouse gases really responsible for changing the global temperature? 12 Ice cores can give us the long view The long view says they are definitely related 2014 397

Increasing Temperatures Correlate with Human Influences 13 Global Temperature and CO 2 Separating Human and Natural Influences on Climate Source: 3 rd US National Climate Assessment, 2014 Source: Global Climate Impacts Report, 2009

The Rate of Warming is Not the Same Around the World 14 Arctic Land Oceans In the past half century: Arctic air temperature increased at 0. 72°F / decade Land surface temperatures increased at 0. 43°F / decade Sea surface temperatures increased at 0. 22°F / decade

The Rate of Warming is Not Even the Same Around the United States 15

What Did We Learn? • The Earth’s temperature is increasing. • This warming (long-term climate change) is caused by increasing greenhouse gas emissions from human activities. • These activities include burning fossil fuels, industrial emissions, agriculture, deforestation. • The biggest greenhouse gases include Carbon Dioxide, Methane, and Nitrous Oxide. • The rate of warming is not the same around the world.

Global CO 2 Emissions and Projections From fossil fuel and cement production. ? Source: CDIAC, Friedlingstein et al. 2014, Global Carbon Project 2014 About 1/3 of the CO 2 from fossil fuel burning remains in the atmosphere after 100 years. About 1/5 of it remains after 1000 years.

NOAA’S NATIONAL CENTERS FOR ENVIRONMENTAL INFORMATION THANK YOU Questions?